Results 101 to 110 of about 15,230 (231)

An unsteady helicopter rotor: Fuselage interaction analysis [PDF]

A computational method was developed to treat unsteady aerodynamic interactions between a helicopter rotor, wake, and fuselage and between the main and tail rotors.
Egolf, T. Alan, Lorber, Peter F.
core   +1 more source

A method for tail rotor aerodynamic force prediction under rotor interference based on coupled momentum source and blade element theory

Xibei Gongye Daxue Xuebao
Due to the influence of slip flow and wake, the tail rotor of a helicopter may produce strong unsteady aerodynamic force in its main rotor interference flow field, which may affect the helicopter control and lead to structural failure.
WEN Long, ZHAO Xu, WANG Weite, LIU Xinyuan, YU Haiyang, HE Long, HE Shun   +6 more
doaj   +1 more source

Reduction of high-speed impulsive noise by blade planform modification of a model helicopter rotor [PDF]

The reduction of high speed impulsive noise for the UH-1H helicopter was investigated by using an advanced main rotor system. The advanced rotor system had a tapered blade planform compared with the rectangular planform of the standard rotor system ...
Conner, D. A., Hoad, D. R.
core   +1 more source

Vibratory Loads Data from a Wind-Tunnel Test of Structurally Tailored Model Helicopter Rotors [PDF]

An experimental study was conducted in the Langley Transonic Dynamics Tunnel to investigate the use of a Bell Helicopter Textron (BHT) rotor structural tailoring concept, known as rotor nodalization, in conjunction with advanced blade aerodynamics as ...
Hamouda, M-Nabil H., Idol, Robert F., Mirick, Paul H., Singleton, Jeffrey D., Wilbur, Matthew L., Yeager, William T., Jr.   +5 more
core   +1 more source

The effect of vortex trap on helicopter blade lift [PDF]

, 2011
The 5-seater Aerospatiale AS350B helicopter has been chosen in this analysis in order to investigate the capabilities of the vortex trap in increasing the helicopter blade lift.
Yaakub, Mohd Fauzi
core  

Performance of an optimized rotor blade at off-design flight conditions [PDF]

An investigation is made of the dynamic and aerodynamic performance of a helicopter rotor previously optimized for minimum 4/rev vertical shear and blade weight subject to certain dynamic and structural constraints.
Chattopadhyay, Aditi
core   +1 more source

Investigation of Helicopter Blade Tip Configuration during Hover Flight Employing Computational Fluid Dynamics

Modelling and Simulation in Engineering
Our research focused on investigating the influence of rotor blade tip geometry on the aerodynamic performance of helicopters during hover flight, with the goal of enhancing overall efficiency.
Soufiane Stouti, Assel Thami Lahlou, Ismail Lagrat, Hamid Mounir, Oussama Bouazaoui   +4 more
doaj   +1 more source

PASSIVE CONTROL OF SHOCK WAVE APPLIED TO HELICOPTER ROTOR HIGH-SPEED IMPULSIVE NOISE REDUCTION

TASK Quarterly, 2010
A strong, normal shock wave, terminating a local supersonic area on an airfoil (or a helicopter blade), not only limits the aerodynamic performance, but also becomes a source of High-Speed Impulsive (HSI) noise.
PIOTR DOERFFER, OSKAR SZULC
doaj  

Structural optimization of composite helicopter rotor blades

, 2020
Structural optimization of a helicopter rotor blade with uniform aerodynamic surface and twist at the functional region is performed for weight minimization subject to various constraints relevant to helicopter rotor blades. The genetic algorithm based optimization is performed only for the functional region of the blade.
openaire   +2 more sources

Results of the flight noise measurement program using a standard and modified SH-3A helicopter [PDF]

A field noise measurement program has been conducted using both a standard SH-3A helicopter and an SH-3A helicopter modified to reduce external noise levels.
Henderson, H. R., Hilton, D. A., Pegg, R. J.   +2 more
core   +1 more source